Despite the concern that has been expressed about potential method biases, and the pervasiveness of research settings with the potential to produce them, there is disagreement about whether they really are a problem for researchers in the behavioral sciences. Therefore, the purpose of this review is to explore the current state of knowledge about method biases. First, we explore the meaning of the terms “method” and “method bias” and then we examine whether method biases influence all measures equally. Next, we review the evidence of the effects that method biases have on individual measures and on the covariation between different constructs. Following this, we evaluate the procedural and statistical remedies that have been used to control method biases and provide recommendations for minimizing method bias.

Sources of Method Bias in Social Science Research and Recommendations on How to Control It

Schizophrenia is a highly heritable disorder. Genetic risk is conferred by a large number of alleles, including common alleles of small effect that might be detected by genome-wide association studies. Here we report a multi-stage schizophrenia genome-wide association study of up to 36,989 cases and 113,075 controls. We identify 128 independent associations spanning 108 conservatively defined loci that meet genome-wide significance, 83 of which have not been previously reported. Associations were enriched among genes expressed in brain, providing biological plausibility for the findings. Many findings have the potential to provide entirely new insights into aetiology, but associations at DRD2 and several genes involved in glutamatergic neurotransmission highlight molecules of known and potential therapeutic relevance to schizophrenia, and are consistent with leading pathophysiological hypotheses. Independent of genes expressed in brain, associations were enriched among genes expressed in tissues that have important roles in immunity, providing support for the speculated link between the immune system and schizophrenia.

/pdf/biological-insights-from-108-schizophrenia-associated-3rfvth8dm9.pdf

Biological insights from 108 schizophrenia-associated genetic loci

Binge eating disorder (BED) is characterized by recurrent episodes of binge eating and, subsequently, significant psychological distress (e.g., shame, guilt). Recently recognized by the American Psychiatric Association (APA) as a distinct eating disorder in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), BED is considered a significant public health problem independently and for its impact on obesity and diabetes. The related problem, loss-of-control (LOC) eating, describes recurrent binge-like eating behavior in individuals who cannot meet full criteria for BED such as post-bariatric surgery patients and children. LOC eating has detrimental psychological and physical health effects, including significant distress and symptoms of depression, as well as excess weight gain in children and suboptimal weight loss and weight regain in post-bariatric patients. Table 1 lists the diagnostic criteria for BED (as defined in the current DSM-5 and earlier, in the DSM, Fourth Edition [DSM-IV]) and frequently-used definitions of LOC eating.

Diagnostic and statistical manual of mental disorders, fifth edition

Current diagnostic systems for mental disorders rely upon presenting signs and symptoms, with the result that current definitions do not adequately reflect relevant neurobiological and behavioral systems - impeding not only research on etiology and pathophysiology but also the development of new treatments. The National Institute of Mental Health began the Research Domain Criteria (RDoC) project in 2009 to develop a research classification system for mental disorders based upon dimensions of neurobiology and observable behavior. RDoC supports research to explicate fundamental biobehavioral dimensions that cut across current heterogeneous disorder categories. We summarize the rationale, status and long-term goals of RDoC, outline challenges in developing a research classification system (such as construct validity and a suitable process for updating the framework) and discuss seven distinct differences in conception and emphasis from current psychiatric nosologies. Future diagnostic systems cannot reflect ongoing advances in genetics, neuroscience and cognitive science until a literature organized around these disciplines is available to inform the revision efforts. The goal of the RDoC project is to provide a framework for research to transform the approach to the nosology of mental disorders.

/pdf/toward-the-future-of-psychiatric-diagnosis-the-seven-pillars-30e28e7cj4.pdf

Toward the future of psychiatric diagnosis: the seven pillars of RDoC

This study shows that every individual has a unique pattern of functional connections between brain regions. This functional connectivity profile acts as a ‘fingerprint’ that can accurately identify the individual from a large group. Furthermore, an individual's connectivity profile can predict his or her level of fluid intelligence.

Functional connectome fingerprinting: identifying individuals using patterns of brain connectivity

/pdf/research-domain-criteria-rdoc-toward-a-new-classification-59j2rllxst.pdf

Charles A. Sanislow

Papers

Research domain criteria (RDoC): toward a new classification framework for research on mental disorders